It's hard to get an accurate picture of why the Bozeman area has had so many more cases of COVID-19 than Missoula County, but there are some numbers behind the issue and it appears Gallatin County has tested a slightly higher percentage of its slightly smaller population.
Gallatin County, home of the city of Bozeman, had tested about 11.53% of its population since the COVID-19 pandemic began and had 791 total cumulative cases as of Monday afternoon. Missoula County has tested about 9.64% of its population and had 212 total cumulative cases as of Monday.
According to Gallatin County communications coordinator Whitney Bermes, Gallatin County had conducted 13,193 tests as of July 25. The county had a population in 2019 of 114,434 based on a U.S. Census estimate.
Bermes said the per capita test percentage doesn't take into consideration people who received multiple tests.
At the beginning of the week of July 20, Missoula County had performed 11,486 tests and had a population estimated to be 119,600, based on the U.S. Census.
That's a lot of numbers, but here come a few more: That means that the positivity rate for Missoula County as of last Monday was 1.84% since testing began.
That's the percentage of tests that came back positive, and doesn't reflect the true percentage of people in the community who have had the virus because not everyone has been tested.
In Gallatin County, the positivity rate since testing began is 5.99% as of Monday.
Bermes noted that health officials in Gallatin County like to use a "seven-day rolling average" to give a clearer picture of more recent positivity rates. For example, the seven-day rolling average of the positive test rate in Gallatin County has been hovering near 10% since July 9.
It's been increasing in Missoula County as well.
"At the beginning of the month our total positivity rate was 1.16%, so it has been steadily increasing," explained Cindy Farr, the incident commander for the Missoula City-County Health Department's COVID-19 response team.
She noted that the county has been averaging about 1,100 to 1,200 total tests per week for the past few weeks.
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